Noise control has always been a problem in connection with industries which require FDA and/or USDA acceptance as, for example, when providing sound barriers to isolate sound emanating from manufacturing areas for food and the like.
The reason for this state of affairs is that, in order to comply with OSHA requirements for noise reduction, the type of acoustical treatment previously available was incompatible with the stringent sanitary requirements of FDA and/or USDA and such acoustical treatment was usually not economically produceable by prior art manufacturing techniques.
The most pertinent prior art sound barrier purporting to deal with these problems is that shown in U.S. Pat. No. 4,094,379 issued June 13, 1978. The barrier in accordance with this patent, however, leaves much to be desired. More specifically, the basic panel is formed of surfaces angularly related to the line of sight thus creating optical distortion when viewing through the panel. Further, the sound absorbing body forming part of the panel is mounted so as to be easily, though inadvertently, displaced or possibly broken loose. Further, such sound absorbing body forms a juncture with the panel proper so as to provide acute angles therebetween defining receptacles for easy accumulation of dirt whereby the cleaning thereof in a manner satisfactory to FDA and/or USDA requirements is rather difficult. Further, the depth of the panel, approximately 4", takes up substantial and valuable space, particularly in a retrofit situation. Further yet, the basic acoustical arrangement of said prior art patent does not provide maximum noise reduction.